It is well established that it is difficult to induce adults and children to brush their teeth on a regular basis. The reasons for this vary from inconvenience and time consuming, to sensitivity and a lack of importance. In addition, children that do not brush from an early age do not develop an appreciation of the benefits of regular brushing. In addition, many people do not understand the importance of brushing. These factors contribute to tooth pain, decay, and eventually to the possibility of loss of teeth. As a result it is important to remove the plaque from the teeth which can be accomplished by acquiring a good brushing technique. It is especially important to detect and remove dental plaque. In an effort to remove plaque from the teeth it is necessary to detect plaque deposits on the teeth. For example, a visible indicator allows detection of areas at which dental cleaning effort should be concentrated. Such plaque deposits can be difficult to detect on the teeth by visual inspection without an indicator. Staining agents for making visible dental plaque are known in the form of solutions, tablets, toothpaste, and gels.
For example, U.S. Pat. No. 3,723,613, discloses a staining agent in tablet form that contains FDC Blue No. 1 and FDC Red No. 3 in order to indicate older dental plaque in dark blue and newer dental plaque in violet-red; this provides important information in regard to the advancement of dental plaque formation and in regard to the treatment thereof.
U.S. Pat. No. 3,903,252, discloses an agent in gel form for making visible dental plaque that contains a pharmacologically harmless organic dye component that is selected from the class of FDC Red No. 3, FDC Blue No. 1, FDC Violet No. 1 and others.
U.S. Pat. No. 4,459,227, discloses a tooth paste containing FBC Blue No. 1 in order to make visible dental plaque. Japanese Patent No. 08059513 A, concerns a solution that contains, inter alia, Red No. 3 and other Reds for making visible dental plaque. The same holds true for Japanese Patent No. 08143477 A. U.S. Pat. No. 4,431,628 A, concerns a composition that contains the natural dye of sugar beets for making visible dental plaque.
European Patent No. 0 421 838, discloses agents for indicating dental plaque formation; the agents contain conventional water-soluble dye FDC Red No. 3. A disadvantage is that FDC Red No. 3 has an unpleasant taste; moreover, in the United States its use as a component of cosmetic products was prohibited in 1989 because its innocuousness had been called into question. According to European Patent No. 0 421 838 B1, the less bitter tasting dye FDC Red No. 40 has been proposed as a substitute dye; this dye has a stronger color intensity in comparison to other dental plaque-indicating agents, for example, FDC Blue No. 1, FDC Blue No. 2, so that these dyes are less useful as dental plaque-indicating agents than FDC Red No. 40.
U.S. Pat. No. 6,485,300, discloses an apparatus for detecting biological deposits on the surface of a tooth. The device has illumination means to direct exciting radiation onto a test tooth surface and detection means to detect fluorescence emission from the test tooth surface at a wavelength associated with that of auto fluorescence emission from clean tooth surface. The intensity of the said fluorescence emission from the test tooth surface is compared with an intensity of auto fluorescence emission from clean tooth surface and the comparison is associated with the presence of deposits on the test tooth surface. The device is preferably embodied in a toothbrush which indicates to the user that deposits are present and are being removed. The entire contents of each of which are incorporated herein by reference.